Jantar Mantar

Jantar Mantar in Jaipur, Rajasthan, is an astronomical observatory built by Maharaja Sawai Jai Singh II between 1728 and 1734 and inscribed as a UNESCO World Heritage Site. It stands beside the City Palace on Gangori Bazaar in the Old City and holds 19 instruments in stone and marble for measuring time, tracking the sun and charting the positions of stars and planets. Visitors walk an open-air courtyard among large geometric structures rather than through galleries. The centrepiece is the Samrat Yantra, a sundial about 27 metres tall and widely described as the largest stone sundial in the world, whose shadow can be watched creeping across its graduated quadrants to give local time to within a couple of seconds. Around it are the Jai Prakash Yantra, a pair of hemispherical bowls with marked inner surfaces, the Ram Yantra cylinders used to measure altitude and azimuth, and the twelve Rashi Valaya instruments, one for each zodiac sign. Small plaques name each instrument, and local guides at the gate explain how they work for a negotiated fee. A typical visit takes one to one and a half hours. Late morning to early afternoon is the best time for reading the sundials because the sun is high and shadows are sharp; early morning light is softer and better for photographs without glare. The courtyard has little shade, so April to June can be punishing. Crowds peak mid-morning when tour groups arrive from the nearby City Palace and Hawa Mahal, and thin out in the last hour before the 5:00PM closing. Photographers tend to favour low angles that frame the curved Jai Prakash bowls and the Samrat Yantra's stair against open sky. Reported 2026 admission is about ₹600 for foreign visitors and ₹100 for Indian visitors, with reduced rates for students.